Process evaluations for cluster-randomised trials of complex interventions: a proposed framework for design and...

Area of Science:

• Health Services Research
• Clinical Trial Methodology

Background:

• Process evaluations are crucial for understanding complex interventions but lack standardized design guidance.
• Current literature emphasizes qualitative methods, neglecting quantitative approaches in process evaluations.
• A framework is needed to structure the design of process evaluations for complex interventions, particularly in cluster-randomised controlled trials.

Purpose of the Study:

• To develop and present a framework to aid researchers in designing process evaluations for complex intervention trials.
• To address the limited guidance available for structuring process evaluations.
• To propose essential reporting elements for process evaluations to enhance their utility and identification.

Main Methods:

• Systematic review of theoretical and methodological literature on process evaluations.
• Analysis of published process evaluations to identify design needs and challenges.
• Iterative development and testing of a novel framework against existing studies.

Main Results:

• A comprehensive framework offering candidate approaches for assessing trial delivery, intervention implementation, and participant responses.
• Identification of key information for reporting in process evaluations to improve clarity and impact.
• Validation of the framework against published process evaluations.

Conclusions:

• No single optimal design exists for process evaluations; choices depend on evaluation goals.
• The developed framework assists researchers in making explicit decisions about research questions and methodologies.
• The framework supports the design of robust process evaluations for complex interventions in trials.